An increasing global population, rising energy demands, and the shift toward a circular bioeconomy are driving the need for more resource-efficient waste management. The increase in the world population—now exceeding 8 billion as of 2024—results in an increased need for alternative proteins, both human and feed grade proteins, as well as for biopolymers and bioenergy. As such, agricultural, forest, and marine waste biomass represent a valuable feedstock for production of food and feed ingredients, biopolymers, and bioenergy. However, the lack of integrated and efficient valorization strategies for these diverse biomass sources remains a major challenge. This literature review aims to give a systematic approach on the recent research status of agricultural, forest, and marine waste biomass valorization, focusing on cascade processing (a sequential combination of processes such as pretreatment, extraction, and conversion methods). Potential products will be identified that create the most economic value over multiple lifetimes, to maximize resource efficiency. It highlights the challenges associated with cascade processing of waste biomass and proposes technological synergies for waste biomass valorization. Moreover, this review will provide a comprehensive understanding of the potential of waste biomass valorization in the context of sustainable and circular bioeconomy.

The aim of this work is to investigate the degradation of low molar mass poly(ethylene terephthalate) (PET)/organically modified montmorillonite (OMMT) clay nanocomposites prepared by melt processing. The rheological behavior in combination with transmission electron microscopic images suggests an intercalation and therefore a percolating network. Furthermore, the results indicate that the increase of organoclay content caused a degradation of PET during processing of PET/OMMT nanocomposites, once it was observed the PET molar mass decreases. The effect mentioned could be attributed to an increase of Brønsted acidic sites on the platelet surface, which is produced by the Hofmann elimination reaction of ammonium, and also the presence of residual metal compounds on clay surface might possibly favored the polymer matrix degradation process.

ABS is widely used as engineering plastic, but extensive use generates a significant amount of waste which is difficult to recycle due to material's complex composition. Physical recycling of ABS using TNO Möbius dissolution technique has been used here to separate pure SAN polymer, from PBR, and other substances. Relationships between properties and composition of the original materials were investigated as a starting point for evaluation of the effects of recycling on the quality of recycled materials. Three ABS materials were used in the recycling process to produce pure SAN polymers. The recycled SANs were then melt-blended with fresh masterbatch. The final ABS ma-terials had the same composition which allowed to investigate whether SAN recycled from different sources causes differences in properties of the final ABS materials. All properties of ABS materials made with recycled SAN are similar regardless of the source of SAN. Substances were quantified in the original ABS materials and in SAN polymers obtained by the recycling process. The substances were largely removed from all materials except one. The main conclusions from this study are that SAN polymer obtained by physical recycling from different sources does not affect properties of the final ABS material and the TNO process successfully separates SAN from other substances.

This study reports the synthesis of a stable and homogeneous nanocomposite of cellulose nanocrystals (CNCs) and vinyl acetate (VA) monomer via a semi‐batch water‐based emulsion polymerization technique, targeting a total solid content (TSC) of 50 wt.% to meet industrial requirements such as smaller storage volume, and easier transportation. The semi‐batch approach enabled a consistent distribution of the reactants and improved scalability for industrial applications. CNCs were successfully incorporated into a polyvinyl acetate (PVAc) latex formulation at concentrations of up to 3.22 wt.% relative to VA monomer. Fourier‐transform infrared spectroscopy indicated the consumption of hydroxyl groups on the CNC surfaces. The nanocomposites containing 1.93% CNC demonstrated the most promising performance, reducing the water sensitivity of pristine PVAc and lowering both the water vapor transmission rate (WVTR) and permeation. Nevertheless, the increased CNC content induced an uneven surface topography and a broader polymer particle size and distribution, as observed by polarized light and scanning electron microscopy. Mechanical testing revealed a general reduction in the tensile properties relative to neat PVAc, although the 1.93 wt. % CNC sample exhibited the least decline. The resulting nanocomposites exhibited an extended shelf life and colloidal stability, indicating their potential for industrial applications.

Plastic litter stranded on beaches is a worldwide problem. The harsh conditions, intense UV radiation, fluctuating temperatures and mechanical abrasion from wind and wave forces, should favour macroplastic degradation and increase fragmentation rate. In a field experiment, ten types of commonly found beach litter items of a variety of polymers, product categories and colours, were placed on two highly exposed beaches on the Swedish west coast. Samples were analysed after 6, 12 and 24 months of exposure, and compared to pristine, un-weathered control items, following degradation by measuring changes in chemical composition (FTIR), thermal properties (DSC), mechanical properties (tensile strength) and morphological feature of surface structure (SEM), while fragmentation was indicated from visual inspection, weight loss and analysis of discolouration. Also after two years’ exposure, only minor signs of chemical and thermal degradation and changes in surface morphology were found. Still, after 6-24 months’ exposure, several litter items, including string (PE), candy paper (LDPE), plastic bag (LDPE), rope (PP), fishing net (PA), container lid (PET), Styrofoam (ESP) and beach toy (PVC) samples, demonstrated decolouration, weight loss and had already fragmented, or were brittle enough to have the potential to do so as shown by major loss (17-71%) in tensile strength. Candy paper lost 71% of tensile strength after 12 months, and after 24 months, samples were transparent and >50% were disintegrated. Our results highlight beach litter as source for microplastic pollution and support management with swift beach cleaning activities of heavily polluted sites to remove macroplastics before microplastics are formed.